Generally, I’d hate to say this, but you need to push through this panicky period. Once your brain gets enough exposure to this activity and realizes it is not some mortal danger you are putting yourself in, the panic will be gone. It does not mean it will not return, but it may return in situations where you really are in danger. So, just dive more. If you do not want to rely on any anxiolytic medication (using which in diving is not a safe practice anyway), just take baby steps. Dive pools, shallow reefs, a bit deeper reefs, and you will see where it takes you.